scholarly journals Incidence and Relative Prevalence of Distinct Caulimoviruses (Genus Caulimovirus, Family Caulimoviridae) Associated with Dahlia Mosaic in Dahlia variabilis

Plant Disease ◽  
2007 ◽  
Vol 91 (9) ◽  
pp. 1194-1197 ◽  
Author(s):  
V. Pahalawatta ◽  
R. Miglino ◽  
K. B. Druffel ◽  
A. Jodlowska ◽  
A. R. van Schadewijk ◽  
...  
Keyword(s):  
United States ◽  
The Netherlands ◽  
Viral Genome ◽  
The United States ◽  
Viral Diseases ◽  
Sequence Variant ◽  
Chain Reaction ◽  
Polymerase Chain ◽  
Relative Prevalence

Dahlia mosaic, caused by Dahlia mosaic virus (DMV), is one of the most important viral diseases of dahlia. Molecular characterization of DMV showed the association of two distinct caulimoviruses (DMV-D10, DMV-Portland) and a D10-like sequence variant (DMV-Holland) with the disease. Using primers specific to these two viruses and the sequence variant, a polymerase chain reaction–based assay was used to determine their relative incidence in several dahlia samples from the United States and the Netherlands. Testing was done on samples collected in 2005 and 2006 in the United States and in 2006 in the Netherlands. Results indicated the predominance of DMV-D10 over DMV-Portland and DMV-Holland in both the United States and the Netherlands. Using conserved regions of the viral genome, primers were designed and used to detect all three sequences. Results suggested that DMV-D10 is predominantly associated with dahlia mosaic, but diagnostics should also include testing for DMV-Portland and DMV-Holland.

scholarly journals Transmission of the Citrus Variegated Chlorosis Bacterium Xylella fastidiosa with the Sharpshooter Oncometopia nigricans

Plant Disease ◽  
2002 ◽  
Vol 86 (11) ◽  
pp. 1237-1239 ◽  
Author(s):  
R. H. Brlansky ◽  
V. D. Damsteegt ◽  
J. S. Hartung
Keyword(s):  
United States ◽  
Polymerase Chain Reaction ◽  
Xylella Fastidiosa ◽  
The United States ◽  
Reliable Indicator ◽  
Symptom Development ◽  
Chain Reaction ◽  
Citrus Variegated Chlorosis ◽  
Specific Polymerase Chain Reaction ◽  
Polymerase Chain

Citrus variegated chlorosis (CVC) is an economically important, destructive disease in Brazil and is caused by the bacterium Xylella fastidiosa Wells. The bacterium has been found to be transmitted in Brazil by sharpshooter leafhoppers (Cicadellidae). Sharpshooters are present in most citrus growing areas of the United States. The sharpshooter leafhopper, Oncometopia nigricans Walker, frequently is found feeding on citrus in Florida. This sharpshooter transmits the X. fastidiosa strains that cause Pierce's disease of grape and ragweed stunt. Research was initiated to determine if O. nigricans was capable of vectoring the X. fastidiosa that causes CVC. In 59 different transmission tests, using 1 to 57 insects per test, transmission of the bacterium was observed 12 times (20.3%). Symptom development in the greenhouse was not a reliable indicator of transmission. Transmission was verified by specific polymerase chain reaction-based assays. Individual insects were able to transmit the bacterium. This information on sharpshooter transmission of CVC is needed to assess the threat posed by the CVC disease to the citrus industries in the United States.

scholarly journals Two Distinct Genotypes of Spissistilus festinus (Say, 1830) (Hemiptera, Membracidae) in the United States Revealed by Phylogenetic and Morphological Analyses

Insects ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 80
Author(s):  
Elizabeth Cieniewicz ◽  
Victoria Poplaski ◽  
Melina Brunelli ◽  
Jason Dombroskie ◽  
Marc Fuchs
Keyword(s):  
United States ◽  
Polymerase Chain Reaction ◽  
Southeastern United States ◽  
Variable Region ◽  
The United States ◽  
Coi Gene ◽  
Its2 Region ◽  
Chain Reaction ◽  
Polymerase Chain ◽  
Spissistilus Festinus

Spissistilus festinus (Say, 1830) (Hemiptera: Membracidae) is a frequent pest of leguminous crops in the Southern United States, and a vector of grapevine red blotch virus. There is currently no information on the genetic diversity of S. festinus. In this study, populations of S. festinus were collected in 2015–2017 from various crops and geographic locations in the United States, and fragments of the mitochondrial cytochrome C oxidase 1 (mt-COI) gene and the nuclear internal transcribed spacer 2 (ITS2) region were characterized by polymerase chain reaction and sequencing. Maximum-likelihood and Bayesian analyses of the mt-COI and ITS2 sequences yielded similar phylogenetic tree topologies, revealing two distinct genetic S. festinus lineages with all of the specimens from California comprising one phylogenetic clade, alongside a single GenBank entry from Arizona, and all specimens from the Southeastern United States comprising a statistically-supported distinct clade, regardless of host and year of collection. The mt-COI gene fragment showed up to 10.8% genetic distance between the two phylogenetic clades. These results suggest the existence of two genotypes within S. festinus in the United States. The only distinct morphological trait between the two genotypes was a less elevated pronotum in the representative specimens from California, compared to the representative specimens from the Southeastern United States. Since this phenotypic feature is inconspicuous, a diagnostic polymerase chain reaction targeting a variable region of the mt-COI fragment was developed to reliably distinguish between the specimens of the two genotypes of S. festinus and to facilitate their specific identification.

scholarly journals Association of Little cherry virus 1 (LChV1) with the Shirofugen Stunt Disease and Characterization of the Genome of a Divergent LChV1 Isolate

2013 ◽  
Vol 103 (3) ◽  
pp. 293-298 ◽  
Author(s):  
Thierry Candresse ◽  
Armelle Marais ◽  
Chantal Faure ◽  
Pascal Gentit
Keyword(s):  
Viral Genome ◽  
454 Pyrosequencing ◽  
Sour Cherry ◽  
Complete Sequence ◽  
Viral Agent ◽  
Chain Reaction ◽  
Independent Source ◽  
Polymerase Chain ◽  
Definite Proof

Double-stranded RNAs purified from the V2356 (‘Successa’) sour cherry source of the Shirofugen stunt disease (SSD) were sequenced using a 454 pyrosequencing multiplex approach. The 15,646 reads obtained were assembled into 279 contigs, 5 of which, totaling almost 16.9 kbp and 5,332 reads (34% of sample reads), showed high Blast scores and homology to Little cherry virus 1 (LChV1). The five contigs were further assembled manually into three supercontigs spanning the full LChV1 genome with only two small gaps (17 and 55 bases). Completion of the sequencing of the viral genome was performed using targeted polymerase chain reaction and primers designed from the contigs. No evidence for the presence of other viral agents in the V2356 source could be obtained in the remaining contigs or singletons. The V2356 LChV1 isolate is only ≈76% identical with the reference complete LChV1 sequences and, in particular, with the ITMAR isolate associated with the Kwanzan stunting syndrome. However, it is highly homologous (97 to 100% identity) in two short genome regions with divergent LChV1 from North America, providing the first complete sequence for such divergent isolates. Although not providing a definite proof, the failure to detect any other viral agent in the V2356 SSD source and the identification of LChV1 in a second, independent, source of the disease suggests that LChV1 isolates could be responsible for the SSD syndrome.

scholarly journals Detection and Characterization of Xanthomonas vasicola pv. vasculorum (Cobb 1894) comb. nov. Causing Bacterial Leaf Streak of Corn in the United States

2017 ◽  
Vol 107 (11) ◽  
pp. 1312-1321 ◽  
Author(s):  
J. M. Lang ◽  
E. DuCharme ◽  
J. Ibarra Caballero ◽  
E. Luna ◽  
T. Hartman ◽  
...  
Keyword(s):  
United States ◽  
Draft Genome ◽  
Housekeeping Genes ◽  
The United States ◽  
Bacterial Leaf Streak ◽  
Diagnostic Assays ◽  
Central United States ◽  
Polymerase Chain

Bacterial leaf streak of corn (Zea mays) recently reached epidemic levels in three corn-growing states, and has been detected in another six states in the central United States. Xanthomonas vasicola was identified as the causal agent of this disease. A multilocus sequence alignment of six housekeeping genes and comparison of average nucleotide identity from draft genome sequence were used to confirm phylogenetic relationships and classification of this bacteria relative to other X. vasicola strains. X. vasicola isolates from Nebraska and South Africa were highly virulent on corn and sugarcane and less virulent on sorghum but caused water-soaking symptoms that are typical of X. vasicola infection on the leaves of all three hosts. Based on host range and phylogenetic comparison, we propose the taxonomic designation of this organism to X. vasicola pv. vasculorum ( Cobb 1894 ) comb. nov. Polymerase chain reaction-based diagnostic assays were developed that distinguish X. vasicola pv. vasculorum and X. vasicola pv. holcicola from each other and from other Xanthomonas spp.

scholarly journals Coccidioidomycosis A Cause of Sarcoidosis

2017 ◽  
Vol 4 (3) ◽  
Author(s):  
Tim Kuberski ◽  
Isaac Yourison
Keyword(s):  
United States ◽  
Lung Biopsy ◽  
Deoxyribonucleic Acid ◽  
Case Reports ◽  
The United States ◽  
Unknown Etiology ◽  
Chain Reaction ◽  
Clinical Observations ◽  
Polymerase Chain ◽  
Endemic Fungi

Abstract Background Sarcoidosis is a granulomatous disease of unknown etiology and coccidioidomycosis is a granulomatous fungal infection endemic to the southwestern United States. Clinical observations on patients with sarcoidosis and coccidioidomycosis simultaneously led to the hypothesis that sarcoidosis can be caused by the fungus Coccidioides. Methods Two patients with sarcoidosis and coccidioidomycosis were studied, one prospectively (ie, a patient with sarcoidosis was predicted to develop coccidioidomycosis) and the other retrospectively (ie, a patient with coccidioidomycosis develops sarcoidosis). In addition, a literature review found 5 patients with these 2 diseases, and they were analyzed to establish an archived relationship between the 2 entities. In addition, polymerase chain reaction (PCR) testing for Coccidioides deoxyribonucleic acid (DNA) was performed on tissue from 15 Arizona patients diagnosed with sarcoidosis. Results Patient 1 was diagnosed with sarcoid in Arizona and followed prospectively. There was no evidence for coccidioidomycosis at diagnosis. This patient was observed for 8 years before he was documented to have disseminated coccidioidomycosis. Patient 2 was retrospectively studied. He was diagnosed with disseminated coccidioidomycosis, but after 3 years, while on antifungal therapy, he developed respiratory failure. A lung biopsy was consistent with sarcoidosis with no evidence of Coccidioides; cultures, histopathology, and serology were all negative. Paradoxically, PCR testing for Coccidioides DNA on tissue taken at the time of the sarcoidosis diagnosis were all negative, including Patient 2 who had proven coccidioidomycosis. Conclusions The 2 study patients and 5 case reports from the literature support the hypothesis that Coccidioides can cause sarcoidosis in Arizona. There are similar reports in the literature that Histoplasma can be associated with sarcoidosis. Based on these observations, we propose that sarcoidosis can be caused by endemic fungi in different areas of the United States, coccidioidomycosis in the Southwest and histoplasmosis in the Midwest.

scholarly journals Ralstonia solanacearum Race 3, Biovar 2, the Causal Agent of Brown Rot of Potato, Identified in Geraniums in Pennsylvania, Delaware, and Connecticut

Plant Disease ◽  
2003 ◽  
Vol 87 (4) ◽  
pp. 450-450 ◽  
Author(s):  
S. H. Kim ◽  
T. N. Olson ◽  
N. W. Schaad ◽  
G. W. Moorman
Keyword(s):  
United States ◽  
Polymerase Chain Reaction ◽  
Bacterial Wilt ◽  
Ralstonia Solanacearum ◽  
The United States ◽  
Enzyme Linked Immunosorbent Assay ◽  
Chain Reaction ◽  
Carbohydrate Utilization ◽  
Tetrazolium Chloride ◽  
Polymerase Chain

The Plant Disease Diagnostic Laboratory of the Pennsylvania Department of Agriculture received diseased geranium (Pelargonium × hortorum) samples from several Pennsylvania (PA) greenhouses in 1999 and 2000 and from one Delaware (DE) greenhouse in 1999. Originating from Guatemala, plants exhibited yellowing, wilting, stunting, and bacterial oozing from the vascular tissues. Isolations on yeast dextrose-CaCO3 (YDC) and triphenyl-tetrazolium-chloride (TTC) agars resulted in off-white mucoid colonies and white, fluidal colonies with pink centers, respectively. Such colonies are typical of Ralstonia solanacearum (1). The disease was similar to a bacterial wilt of geranium caused by an unidentified biovar of R. solanacearum (3). Preliminary tests using Biolog MicroLog 3 (Hayward, Ca; 4.01A) and enzyme-linked immunosorbent assay (ELISA) (Agdia Inc., Elkhart, IN; BRA 33900/0500) identified the organism as R. solanacearum. For pathogenicity tests, a 10-μl droplet of water suspension containing 1 × 106 CFU of each of five geranium strains (PDA 22056-99, 81849-99, 81862-99, 51032-00, and 64054-00) per milliliter was placed on a stem wound made by cutting off the terminal growth of each of 4 6-leaf stage plants of geranium ‘Orbit Scarlet’, tomato ‘Rutgers’, potato ‘Russet Norkotah’, and eggplant ‘Black Beauty’ in a growth chamber at 28°C, 86% relative humidity, and 12 h light/dark cycle. Water was included as a control. The five strains caused severe yellowing and wilting within 10 days. Colonies typical of R. solanacearum were reisolated from symptomatic tissue on YDC and TTC. To determine the specific biovar, 20 pathogenic geranium strains from PA and DE plus a strain of R. solanacearum originally isolated from a geranium plant of Guatemalan origin received from Connecticut in 1995 were grown up to 28 days on Ayers mineral medium supplemented with a 1% final concentration of D-cellobiose, dextrose, meso-inositol, lactose, maltose, D-ribose, trehalose, mannitol, sorbitol, or dulcitol (1). Acid was produced by 21 test strains from the first five carbohydrates only. Such carbohydrate utilization is typical of bv 2 (1). Bv 2 identification was confirmed by real-time polymerase chain reaction using bv 2-specific primers and probes (N. Schaad, unpublished) designed from a bv 2-specific DNA fragment (2). All tested strains were positive using ELISA. In contrast, strains of bv 2 from geraniums in Wisconsin and South Dakota were reported to be negative using ELISA (4). From our results, it appears that bv 2 was introduced into the United States on geraniums from Guatemala in 1995 and 1999. This cool climate bv 2, a regulated agent by the Agricultural Bioterrorism Protection Act of 2002, has caused extensive crop loss in potatoes in Europe, but has not been found in potatoes in the United States. References: (1) T. P. Denny and A. C. Hayward. Ralstonia solanacearum. Pages 151–174 in: Lab Guide for Identification of Plant Pathogenic Bacteria. N. W. Schaad et al. eds. 3rd ed. The American Phytopathological Society, St. Paul, MN, 2001. (2) M. Fagen et al. Development of a diagnostic test based on the polymerase chain reaction (PCR) to identify strains of R. solanacearum exhibiting the Biovar 2 genotype. Pages 34–43 in: Bacterial Wilt Disease: Molecular and Ecological Aspects. P. H. Prior et al. eds. Springer-Verlag, Berlin, 1998. (3) D. L. Strider et al. Plant Dis. 65:52, 1981. (4) L. Williamson et al. (Abstr.) Phytopathology 91 (Suppl.):S95, 2001.

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